Power amplifying positioning device



Sept. 11, 1934. J c ALBmGHT 1,972,852

POWER AMPLIFYING POSITIONING DEVICE Original FiledNov. 26, 1930 3 V g i4 k w l9 v I r 3 3 INVENTOR Joseph QAlbTight. 2 BY ATTO EY PatentedSept. 11, 1934 UNITED STATES PATENT. OFFICE.

POWER AMPLIFYING POSITIONING DEVICE Joseph C. Albright, Teaneck, N. J.,assignor to Bailey Meter Company, a corporation of Dela- 3 Claims. '(Cl.60-52) This invention relates in general to devices wherein thepositioning of a member by a relatively weaker control force results in'the positioning of another member by an amplified or 5 relativelygreater force to accomplish a useful position; but in any event thesecond member'is caused to move or to be positioned as the resultof achange in position of the first member, and with a force relativelygreater than the force imparted to the first member.

The first member may be positioned or caused to depart from a givenposition through various causes; for example, by variations in pressure,

differential pressure, temperature, rate of fluid fiow, or in fact anyvariable factor or relation whose force is desirably magnified toposition a second member requiring a .relatively greater force for suchpositioning. The second member so positioned may move an indicator orcan be used to move a damper or valve or desirable regulable mechanismwhose movement may or may 'not resultin a change in value of the factorwhich caused the initial movement of the first member. v

My invention resides in certain improvements and arrangement of parts,in such devices wherein many advantages are obtained.

One object'is to provide such a torque or power amplifier utilizinghydraulic power.

Another object is to arrange the hydraulic power producing andcontrolling parts in a single unit.

A further object is to provide means wherein the movement of thesecondary member may bear a desirable relation to the movement of theprimary member.

I A still 'further object is to provide a construction wherein thepilot'controlling the passage of hy2lraulic fluid moves axially relative'to and .rotor 4, and capable of axial positioning through within theamplified power piston.

Another object is to provide a construction wherein the pump forproviding hydraulic fluid. is located in and axially mo ved with theampli-' 'fied power-piston.

,A' still further object are have the jmovma;

of the second member result in shuttingofl oi? the amplified powereffective in causing such a movement.

With these and further objects in view I will now describe a preferredembodiment of my invention.

In the drawing:

Fig. 1 is an arrangement, partly diagrammatic and partly in sectionalelevation of an embodiment of the invention wherein is shown a certainpreferred arrangement of parts.

Fig. 2 is a sectional elevation along theline 2-2, in the direction ofthe arrows, of Fig. 1.

Fig. 3 is a section in plan along the line 3 3; in the direction of thearrows, of Fig. 2.

I have illustrated an arrangement wherein an amplified power piston islocated concentric with and movable axially relativeto a pilot, andwherein means for providing hydraulic fluid under pressure forpositioning the power piston is located in and axially positioned withthe power piston.

A casing 1 has cooperating therein a piston 2 which in turn encasesasleevev member-3 carrying at its lower end the rotor 4 of a pump forproviding hydraulicfluid under pressure. Within the sleeve member 3 andaxially movable therein is a pilot 5 having lands spaced along thelength of the pilot, cooperating with ports or passages through thesleeve member. I

I have shown the pilot 5 capable of being positioned axially in theassembly by variations in pressure of a fluid in a duct 6 effective atthe pipe 7 upon a Bourdon tube 8 and through the intermediary of alinkage 9. The link 9, pivotally connected to the pilot 5 forpositioning the same, further carries an extension forming a pointer 9Acooperating withan index 9B, for advising the value of the fluidpressure and/or of the position axially of the pilot 5.

To overcome a tendency toward resistance to axial positioning of thepilot 5 I preferably rotate the sleeve 3, and in so doing eifect anoperation of the pump rotor 4. Such rotation is obtained from a motorshown at 10, driving through suitable gearing a shaft 11 carryingthereon a worm 12 meshing with and driving a worm wheel 13 splihedto thesleeve 3 at 14. The sleeve member 3 is thus continually rotated, drivingthe pump the medium of the spline 14.

Thepump as shown'more in detail in Fig. 3

hasa stationary part 15 of the piston 2 forming ashield between therotor'4 and a rotor 16, the

between its ends and moves in effect relative to the cylinder 1 as thepiston is vertically positioned in the cylinder. A passage 19 permitshydraulic fluid, preferably oil, to enter the pump from the reservoirv18. The oil is'then discharged, when needed, through a passage 20 to anannular channel 21 around the sleeve member 3, said channel having anopening at one or more points through the sleeve to the interior of thesleeve and between the lands of the pilot 5.

A passage 22communicates between the interior of the sleeve member 3 andthat part of the cylinder 1 below the piston 2, while a passage 23communicates between the interior of the sleeve member 3 and that partof the cylinder 1 lying abovethe piston 2. A drain is provided from theinterior. of the sleeve 3 through a passage 24 to the reservoir 18 frombelow the pilot 5, while a drain from above the lands of the pilot 5 isprovided through the passage 25 down through the pilot, to communicateto the space below the pilot and the drain connection 24.

Vertical motion or positioning of the piston 2 within the cylinder 1 istransmitted external of the cylinder through a rack 26 driving a pinion'27, the pinion having a shaft 28 extending through suitable fluid tightbushings externally to position an indicator 28A relative to an index28B, or as shown in Fig. 1, through proper gearing, position a damper29to control the pressure effective at the pipe 7. I d

In operation, a change in pressure within the duct 6 results in amovement of the Bourdon tube '8, and assuming that the pressure hasincreased, then the Bourdon tube tends to move counterclockwise andpo'sitionsthe pilot downwardly so that the lands move downwardly out ofalignment with the ports in the'sleeve'3. If the pump rotor 4 is beingrotated byithe motor 10, then hydraulic fluid under pressure isavailable through the passage 20 and the annular chamber 21 at theinterior of the sleeve 3 between the lands of the pilot 5 Immediatelyupon movement of the lands downwardly 'out of alignment with the ports,there will be a flow of hydraulic fluid through the passageway 23 to theupperside of the piston 2, and simultaneously a drainage of fluid frombelow the piston 2 through the passage 22, the opening 25 and the drainpassage 24, all resulting in a downward movement of the piston 2 anamount proportional to the displacement of the pilot from its originalposition, The downward motion of the piston 2 results in a positioningof the ports opposite the lands to shut off flow of hydraulic fluid, as.well as rotation of the externally extending shaft 28 which may positionan indicator 28A of the pressure effective at the pipe '7, or position adamper or valve means 29 to control such pressure. In any event, theshaft extension 28 is positioned to a definite point for each pressurewithin the range of operation, and with a power amplified over thatavailable to position the pilot 5 through the linkage 9.

So long as the lands of the pilot 5 are aligned with the ports of thesleeve 3, no hydraulic fluid passes through the ports from the pumprotor 4, and assuming that the rotor is in continued rotation, thenpressure developed thereby is relieved from passage 20 to reservoir 18through a ballv valve 30 spring backed by a spring 31.

I have provided an amplified power positioning device wherein arelatively weaker control force positions a member to result in thepositioning of a second member with greater force, thereby indie catingthe positioning or movement of the first member as an indication of theposition or variation in position or amount of a factor whose variationresults in the relatively weaker control force; or the motion of thesecond member having rela tively greater power may accomplish usefulwork such as controlling the factor, or some other factor.

I preferably provide that a self-contained, compact unit is formedwherein the controlling pilot is surrounded by the amplified powerpiston which further carries the pump for supplying hydraulic fluidunder pressure. It will 'be understood that I have illustrated anddescribed a certain pre-. ferred embodiment of my invention, but that Iam not to be limited thereby other than as claimed in view of prior art.

What I claim as new anddesire to secure by Letters Patent of the UnitedStates, is:

1. In a power amplifying mechanism, in combination, an axially movablepilot-capable of being positioned by a relatively weak control force, arotatable and axially movable sleeve surrounding the pilot and havingports for the passage of hydraulic fluid, rotating means for saidsleeve, a fluid pump fastened to said sleeve and operated thereby, anaxially movable piston defining a casing for the sleeve and the pump andcooperating in a'cylinder, fluid passages in the piston, the i pilotarranged upon axial positioning to control passage of hydraulic fluidfrom the pump to the 1115 cylinder at one end or the other of the pistonto cause a movement thereof, said movement effecting a closing ofpassage to said cylinder, the wall of said piston intermediate its endsdefining with the wall of said cylinder a fluid storage space, and meansextending external of the cylinder posi-' tioned by the piston.

2. In a power amplifying mechanism, in combination, a source ofhydraulic fluid, a cylinder, a pilot for controlling passage of thehydraulic fluid to the cylinder, a piston positioned in the cylinder bythe hydraulic fluid, the piston surrounding the pilot and capable ofbeing positioned axially relative to the pilot, a pilot sleevesurrounding the pilot and adapted for axialmovement relative to thepilot, a fluid pump carried by the sleeve, and rotatingv means for thepilot sleeve. X

3. In combination, a member capable of, being positioned by a relativelyweaker control force and comprising a pilot, fluid means controlled bythe pilot to provide an amplified force, a piston positioned in acylinder by said fluid means, the piston concentric with the pilot, apilot "sleeve surrounding the pilot forming a casing therefor andadapted for axial movement relative thereto, a fluidpump carried by thesleeve, and rotating means for the sleeve.

JOSEPH C. ALBRIGH'I'.

